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Сейсмостойкое строительство. Безопасность сооружений. 2018 - №1

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Studying the dynamics of seismically isolated buildings with the aid of the stations of engineering seismometric service

Authors:    Yerzhanov S.Е.    Vladimir A. Lapin    Daugavet V.   
Rubric:     Theoretical and experimental studies   

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In KazNIISA JSC studies of seismic isolating properties of buildings equipped with special earthquake protection systems are carried out at the special field test site. Displacement, velocity and acceleration measuring sensors were installed on three houses constructed with the same above-foundation part (9-storey large-panel houses of series 158), but with different foundations: conventional strip foundations with the system of crossstrips, seismically isolating kinematic foundations and supports with PTFE gaskets. On these buildings instrumental records of the earthquake were received in the transverse direction on August 16, 2014. The resulting accelerograms were used to construct spectral curves ?. The possible effect of seismic isolation, as well as the influence of foundation constructions on the dynamics of buildings with foundations of conventional type and seismically isolated ones is assessed.


Fire in high-rise buildings

Authors:    Krivtsov Yu.V.    Ladygina I.R.    Nosov E.N.   
Rubric:     Seismic safety and seismic isolation of buildings   

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More than 70 fires in high-rise buildings in Russia and abroad are analyzed. Recommendations for fire safety in high-rise buildings are made.


How do the shock absorbers work for the seismic protection of buildings? Investigation of the question by numeric simulations. Part 2.

Authors:    Makarov S.    Pankova N.    Tropkin S.   
Rubric:     Theoretical and experimental studies   

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A computer study on seismic protection is presented. Part 1 has shown that passive rubber-like shock absorbers in the foundations of buildings are often not effective enough. The purpose of this work is to look at the possibility of applying an unconventional approach for seismic protection tasks. A model task is used to change the resonant properties of the protected object by applying a passive multifrequency dynamic vibration absorber. Indeed, in the absence of specific information on a possible earthquake under a particular building – on the direction of its impact, on its frequency components, which can coincide with the resonant frequencies of the protected building, etc., how to protect the object? Computer simulation showed that if the damper considered in Part 1 is used as a passive multifrequency dynamic absorber, placed on the roof of the building, then it is possible to obtain a noticeable effect of reduced resonant peaks. 


Землетрясение знает о себе все. Сейсмолог Татьяна Раутиан – о том, почему сложно предсказывать стихийные бедствия

Authors:    Kudriavtseva E.V.   
Rubric:     News / Events   

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Почему наука так и не научилась предсказывать землетрясения, как реагирует земля на ядерные взрывы и в чем был не прав академик Андрей Сахаров? Обо всем этом «Огоньку» рассказала Татьяна Раутиан, проработавшая более 40 лет в составе крупнейшей в СССР сейсмологической экспедиции на Памире, единственная россиянка, награжденная медалью Рида американского Сейсмологического общества, которую вручают «великим сейсмологам мира». Памирская Комплексная сейсмологическая экспедиция (КСЭ) Института физики Земли АН СССР была легендарной – она впервые в нашей стране начала систематически изучать сейсмологические явления и искать причины землетрясений, их предвестники и в целом познавать природу этой катастрофы. Работа ученых началась в 1950 году в маленьком поселке Гарм в предгорьях Памира и закончилась лишь спустя четыре десятилетия, в 1992 году, в связи с гражданской войной в Таджикистане. Четверть века тишины Начиналась экспедиция с одиночной станции, которая фиксировала колебания Земли способами, принятыми в канун Первой мировой войны. Спустя четыре десятка лет, когда сворачивали работу, это была уже мощная разветвленная сеть сейсмостанций, которые вели сплошную запись землетрясений, с громадным штатом, бюджетом и хозяйством. На основе полученных данных ученые делали самые разные открытия, которые касались природных катаклизмов, строения Земли и... ядерных взрывов. Ошибки нет: экспедиция много лет сотрудничала с Министерством обороны СССР, выполняя секретные работы по определению эпицентров ядерных взрывов по всему миру. Татьяна Глебовна Раутиан проработала в составе Комплексной сейсмологической экспедиции Гарма много лет – и как исследователь, и как руководитель (заместитель начальника по науке). После распада СССР ее пригласили в Ламонтскую геофизическую обсерваторию Колумбийского университета в США. Сейчас она в Москве – изучает архивы, издает семейный альманах и... учится играть на фортепиано. Но говорим мы с ней, понятно, о главном в ее жизни – о сейсмологии.


Review of typical accidents with vertical cylindrical storage tanks during earthquake

Authors:    Shigapov R.R.    Kovalchuk O.A.   
Rubric:     Seismic safety and seismic isolation of buildings   

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A significant quantity of vertical cylindrical storage tanks is being built in earthquake-prone regions. The present paper gives data on tank accidents as a result of seismic events of the 20th and 21st centuries and describes typical incidents and their scenarios during the earthquakes in Coaling (California, USA), Niigata, Tokachi-Oki and Tohoku (Japan), Emilia (northern Italy). During the research work, risk factors and typical consequences of accidents were analyzed for tanks of different sizes. Some recommendations for increasing seismic resistance of storage tanks are given as a result of the analysis.


Contribution of damping to the dynamic loads in seismic analysis

Authors:    Tyapin A.G.   
Rubric:     Theoretical and experimental studies   

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Development of linear equations of motion for seismic analysis is discussed in the paper. Surprisingly, there are still some non-trivial issues. The paper is a polemic one: the author does not agree with colleagues putting damping matrix into the right-hand part of the equation of motion. In the author’s opinion, the mistake is in the implementation of the Rayleigh damping model for the right-hand part of the equation. This is in the contradiction with physical logic, as damping in the Rayleigh model is not really “internal”: due to the participation of the mass matrix it works on rigid displacements, which is impossible for internal damping. The author is sure that physical logic should have a priority against any approximate mathematical model, so the contribution of the internal damping to the right-hand part of the equation shall be excluded before this or that model of internal damping is chosen. Besides, the author asks two more questions about the internal forces calculations. He hopes to get response from the colleagues on these issues.


The maximum principle of Pontryagin and emergency seismic load

Authors:    Vedyakov Ivan I.    Vladimir K. Vostrov   
Rubric:     Theoretical and experimental studies   

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The work proposes the methods for determining special and emergency seismic loads and emergency calculation situations required in accordance with the current legislation. It is refined the previously proposed way of describing the structure movements with the help of nonlinear ordinary differential equations and the existence of stable limit cycles for them, leading to the appearance of stationary periodic solutions-self-oscillations. It is shown that the task of selecting a special (emergency) seismic action is reduced to the task of optimal speed, when the transition from one extreme position of the structure to another with external seismic action takes place in a minimum time. A proposal was made to apply special (emergency) harmonic seismic actions with a special frequency close to the natural oscillation frequency of the structure as a maximum design earthquake in seismic regions. Emergency seismic horizontal loads are allocated as loads that create an emergency situation. An algorithm for determining the special frequency of emergency seismic actions is presented. It is based on the comparison of the maximum displacements of structures arising from beats and self-oscillations.